[BreachExchange] Docker Hub Breached, Impacting 190,000 Accounts

[Destry Winant]

https://www.eweek.com/security/docker-hub-breached-impacting-190-000-accounts

Docker is warning of a data breach that impacts some 190,000 users of
its Docker Hub repository for container images.

The breach was first reported by Docker late on April 26 in an email
sent to Docker Hub users, revealing a data breach that was detected
the day before, on April 25. Docker Inc. is the lead commercial
sponsor behind the open-source Docker container technology that
enables developers to build, package and deploy applications as
containers. The Docker Hub is a popular repository for Docker users to
find freely available Docker application images to run.

"During a brief period of unauthorized access to a Docker Hub
database, sensitive data from approximately 190,000 accounts may have
been exposed (less than 5% of Hub users)," Kent Lamb, director of
Docker Support, wrote in an email sent to Docker Hub users. "Data
includes usernames and hashed passwords for a small percentage of
these users, as well as GitHub and Bitbucket tokens for Docker
autobuilds."

Docker Hub was launched in June 2014 by Docker Inc. alongside the
company's Docker 1.0 release. The new data breach disclosure comes at
a particularly inopportune time for Docker, as its DockerCon
conference begins on April 30 in San Francisco.

Breach Impact

According to Docker, the data breach involved unauthorized access to a
single Docker Hub database that was only storing a subset of
nonfinancial user data. At this time, it is not clear how the breach
happened or how long attackers may have had unauthorized access.

Docker Hub contains many different types of application images and is
used by a wide variety of users. Docker emphasized in an FAQ about the
incident that no official application images were  compromised.
Official images are those developed by Docker and its partners that
benefit from additional authenticity and scrutiny.

"We have additional security measures in place for our Official Images
including GPG signatures on git commits as well as Notary signing to
ensure the integrity of each image," Docker stated.

Notary is a code signing technology that makes use of the open-source
The Update Framework (TUF), which provides multiple layers of
verification and checking to help maintain the security and
authenticity of application images and their updates.

The breach is particularly relevant for developers, more so than just
regular users of Docker Hub.

"For all Docker Hub users, there is no action required to preserve
your security," Docker stated. "A password reset link has been sent to
any users who potentially had their password hash exposed."

Docker is widely used as part of a DevOps tool chain in which code
developed on GitHub and Bitbucket is automatically built at periodic
intervals, with container images automatically deployed to Docker Hub
as part of the build process.

"Users who have autobuilds who have had their GitHub or Bitbucket
repositories unlinked will need to relink those repositories," Docker
stated.

Analysis

"There could be quite a broad impact from this attack—but it’s too
early to know at this point," John Morello, CTO at Twistlock, wrote in
a blog post. "Access to a Hub account means read/write access to repos
that anyone on the internet can easily reuse with a simple docker pull
myrepo/myimage."

Morello added that any Docker Hub user who has connected their account
to GitHub should review access to identify any potential anomalies.

Overall, Docker recommends that impacted users:

- Change their Docker Hub account passwords.
- Review GitHub activity.
- Unlink and then relink GitHub access.